• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1379-1381
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• 2004

This paper presents the AC electric railway system modeling using PSCAD/EMTDC program. This system model is composed of the scott-transformer the auto-transformer. the running rails. the protection wires, the feeders. the catenary and contact wires, etc. After obtaining the models of the fundamental elements describing the AC electric railway system and its behavior, we have analyzed and tested real traction power feeding system focused on the amplification of harmonic current to verify the proposed model. The simulation results from the proposed approach and the measurement data from the test are described in the paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1669-1671
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• 2005

This paper presents an effective modeling scheme of SPE cell system for hydrogen production. PSCAD/EMTDC model of SPE cell system for hydrogen production to efficiently utilize Solar cell energy which produces effectively hydrogen energy is showed in this paper. The simulated results are then verified by comparing them with the actual values obtained from the data acquisition system. Authors are sure that it is a useful method to the researchers who study SPE cell system for hydrogen production.

• KIEE International Transactions on Power Engineering
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• 제3A권3호
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• pp.148-154
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• 2003

This paper describes the development of KEPCO's 80MVA UPFC electromagnetic transient model and the analysis of its performance in the actual Korean power system. KEPCO's 80MVA UPFC is currently undergoing installation and will be ready for commercial operation from the year 2003. In order to apply a new FACTS device such as the UPFC to the actual power system, the utility needs, in advance, both load flow stability studies and transient studies. Therefore, KEPRI, the research institute of KEPCO, developed a detailed transient analysis model that is based on the actual UPFC S/W algorithm and H/W specifications. This simulation model is implemented by an EMTDC/PSCAD package. The results of the simulation show the effectiveness of UPFC operation in the KEPCO power system.

• 전기학회논문지
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• 제57권6호
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• pp.985-993
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• 2008

This paper proposes a new DFIG(Doubly-Fed Induction Generator) system using matrix converter, which is very effectively used for interconnecting the wind power system to the power grid. The operation of proposed system was verified by computer simulations with PSCAD/EMTDC software. The feasibility of hardware implementation was conformed by experimental works with a laboratory scaled-model of wind power system. The laboratory scaled-model was built using a motor-generator set with vector drive system, and a matrix converter with DSP(Digital Signal Processor). The operation of scaled-model was tested by modeling the specific variable-speed wind turbine using the real wind data in order to make the scaled-model simulate the real wind power system as close as possible. The simulation and experimental results confirm that matrix converter can be applied for the DFIG system.

• Journal of Electrical Engineering and Technology
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• 제12권1호
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• pp.11-18
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• 2017

In order to maintain customer voltages within the allowable limit($220{\pm}13V$) as much as possible, tap operation strategy of SVR(Step Voltage Regulator) which is located in primary feeder, is widely used for voltage control in the utilities. However, SVR in nature has operation characteristic of the delay time ranging from 30 to 150 sec, and then the compensation of BESS (Battery Energy Storage System) during the delay time is being required because the customer voltages in distribution system may violate the allowable limit during the delay time of SVR. Furthermore, interconnection of PV(Photovoltaic) system could make a difficultly to keep customer voltage within the allowable limit. Therefore, this paper presents an optimal coordination operation algorithm between BESS and SVR based on a conventional LDC (Line Drop Compensation) method which is decided by stochastic approach. Through the modeling of SVR and BESS using the PSCAD/EMTDC, it is confirmed that customer voltages in distribution system can be maintained within the allowable limit.

• 전기학회논문지
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• 제56권1호
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• pp.8-13
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• 2007

During the last years, there has been an increased interest in the new energy such as photovoltaic(PV) system from the viewpoint of environmental pollution. In this regard, this paper estimates the power quality of grid-connected PV system. As the maximum power operating point(MPOP) of photovoltaic(PV) power systems alters with changing atmospheric conditions, the efficiency of maximum power point tracking(MPPT) is important in PV power systems. Moreover, grid-connected PV system occurs some problems such as voltage inequality and harmonics. Therefore, this paper presents the results of a grid-connected PV system modeling that contains incremental conductance MPPT controller by PSCAD/EMTDC simulator and investigates the influence that can occur in the grid-connected PV system from aspect of power quality, i.e. voltage drop, total harmonic distortion(TDD) and total demand distortion(TDD). For the case study, the measured data of the PV way in Cheongwadae, Seoul, Korea is used.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.228-230
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• 2002

Recently, electric power reliability of our country has been improved. However, there are still remaining problems which are short-duration variations like instantaneous and momentary interruption and voltage sag by nature calamity ; typhoon, lightning, snow, etc. Besides, power quality ; harmonics, caused by using power electronics equipments, become a hot issue Malfunction of controller and stop machinery, and losing the important data are caused by poor power quality at a couple of second. Due to those, UPS, which is made up battery, has being used, but there are several disadvantages ; long charge and discharge time, environmental problem by acid and heavy metal, and short life time. As generally know, micro-SMES is a method to settle those mentioned. However, there need huge system apparatuses in order to verify the effect of system efficiency and stability considering the size of micro-SMES, the sort of converter type, and various conditions ; inner temperature, magnetic field, quench characteristic of micro-SMES, and etc. In this paper, in order to bring the mentioned above to a settlement, a micro-SMES is modeled with characteristics of micro-SMES is interfaced to EMTOC program using Fortran program interface method. We obtained hopeful answers and made the simulation model of micro SMES.

• 조명전기설비학회논문지
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• 제20권3호
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• pp.12-19
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• 2006

마이크로소스는 1[kW]${\sim}$수[MW] 사이의 전력을 공급하고, 기존의 대규모 발전설비보다 높은 신뢰도와 에너지 효율을 가지는 고품질의 전력을 공급할 수 있다. 본 논문에서는 마이크로소스의 스위칭레벨 모델을 개발하였으며, 다수의 마이크로소스가 전력시스템과 연계되어 마이크로그리드를 형성할 경우의 특성에 대하여 연구하였다. 마이크로소스는 인버터의 효율을 극대화 할 수 있도록 공간벡터 펄스폭변조(Space Vector PWM, SVPWM) 기법을 채용하였으며, 마이크로소스의 제어시스템 파라미터 특성 및 마이크로소스 상호작용에 관하여 연구하였다. 마이크로소스는 PSCAD/EMTDC를 이용하여 구현하였으며 이를 이용해 마이크로그리드를 구성하여 시뮬레이션하였다. 사례 연구를 통하여 제안된 모델의 효용성을 확인하였다.

• 한국산학기술학회논문지
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• 제20권11호
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• pp.239-249
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• 2019

최근, 정부는 신재생에너지전원을 확대하는 정책을 시행하고 있으며, 이에 따라 다수의 대용량 태양광전원이 배전계통에 활발하게 연계되고 있는 실정이다. 하지만, 이러한 태양광전원이 배전계통에 연계되는 경우, 역조류 현상에 의하여 수용가 전압이 규정전압범위를 벗어날 가능성이 있다. 이러한 문제점을 해결하기 위하여, 배전계통에서 태양광전원의 수용성을 향상시키기 위한 연구가 활발히 이루어지고 있다. 따라서, 본 논문에서는 선로절체에 의한 태양광전원의 수용성 향상을 위하여, 배전계통 상용해석 프로그램인 PSCAD/EMTDC를 이용하여, 3분할 3연계로 구성된 배전계통의 모델링을 제시하고, 태양광전원을 최대한 수용할 수 있는 선로절체 평가알고리즘을 제시한다. 또한, 배전선로 절체 구간 및 태양광전원 연계 용량 등의 다양한 운용 시나리오에 기반하여, 변압기 2차측 직하 수용가전압을 규정전압범위 이내로 유지하는 최대 태양광전원 용량을 산정하기 위하여 최적의 선로절체 구간을 산정한다. 제안한 배전계통의 수용성 평가알고리즘과 모델링을 바탕으로 수용가전압 특성을 분석한 결과, 대용량 태양광전원이 연계된 배전선로를 용량의 여유가 남아있는 선로와 절체하여 재구성하게 되면, 더 많은 용량의 태양광전원의 연계가 가능하여, 본 논문의 유용성을 확인하였다.

• 한국융합학회논문지
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• 제2권2호
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• pp.47-56
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• 2011

2008년도 지식경제부의 전망에 의하면 신재생에너지전원 중 풍력발전의 보급전망은 2020년 37%, 2030년 42%에 달하고, 2012년부터 시행 예정인 신재생에너지 의무할당제(Renewable Portfolio Standard-RPS)의 도입으로 태양광 및 풍력 등의 신재생에너지가 향후 지속적으로 배전계통에 연계 운용될 것으로 예상된다. 현재 풍력은 배전계통에 전용선로로 연계되어 계통에 미치는 영향은 미미하지만, 3[MW] 이상의 대규모 풍력발전이 일반 배전선로로 확대 운용되면, 풍력발전 연계용 변압기 및 풍력발전기의 %임피던스에 의한 사고전류 변동으로 보호계전기(OCR, OCGR)의 오 부동작을 야기할 수 있다. 따라서 본 논문에서는 대표적인 풍력발전기인 이중여자유도발전기(Double-Fed Induction Generator-DFIG)가 고압 배전선로에 연계되어 운전되는 경우, 3상단락, 2선단락 및 1선지락의 사고특성을 분석하기 위하여, 전력계통 상용소프트웨어인 PSCAD/EMTDC를 이용하여 풍력발전기의 모델링과 시뮬레이션을 수행하고, 대칭좌표법을 통한 이론적인 수치해석의 결과치를 비교/분석하여, 제안한 수법의 유용성을 확인하였다.